Questions tagged [check-constraints]

That part of declarative referential integrity (DRI) where a column's permitted range of values is enforced by a Boolean predicate.

Filter by
Sorted by
Tagged with
22
votes
2answers
42k views

Disable all constraints and table checks while restoring a dump

I've obtained a dump of my PostgreSQL database with: pg_dump -U user-name -d db-name -f dumpfile which I then proceed to restore in another database with: psql X -U postgres -d db-name-b -f ...
20
votes
1answer
2k views

Postgres: How is SET NOT NULL “more efficient” than CHECK constraint

In PostgreSQL docs for Constraints, it says A not-null constraint is functionally equivalent to creating a check constraint CHECK (column_name IS NOT NULL), but in PostgreSQL creating an explicit ...
3
votes
1answer
9k views

Check constraint references another column in same table

I have this table but check constraint is throwing me an error: Column CHECK constraint for column 'MedicamentRegulated' references another column, table 'Medicaments'. I've seen this as allowed ...
3
votes
2answers
15k views

Check Constraint with Case Statement

I want to add a check constraint on a column if entered value for column is greater than 3 than it should be saved as 1 else entered value. For that scenario I am using below query but on insertion of ...
29
votes
2answers
40k views

ALTER TABLE CHECK CONSTRAINT

From the Object Explorer in SQL Server, when selecting and scripting a foreign-key constraint, the following code is generated. USE [MyTestDatabase] GO ALTER TABLE [dbo].[T2] WITH ...
1
vote
2answers
1k views

Constraint for multiple foreign key yet it's mutually exclusive (PostgreSQL)

Loan table associated to due table. also Invoice table associated to due table. In due table either one of them foreign key should present and other one should be null. What kind of constraint ...
4
votes
4answers
10k views

ERROR: check constraint is violated by some row

I've got the following error: ERROR: check constraint "cc_at_least_one_mapping_needed" is violated by some row Query: ALTER TABLE integrations.tax_aggregates DROP COLUMN IF EXISTS myob_id, ADD ...
3
votes
1answer
3k views

Is varchar(x) as fast as `text CHECK ( char_length(x) )`?

In an Twitter exchange, Simon West asks to Brandur, Out of interest, why do use email TEXT CHECK (char_length(email) <= 255) rather than email VARCHAR(255)? Not a pattern I've seen before ...